This invention relates to power supplies for use with digital systems such as computers, computer peripheral equipment, displays in which characters are repetitively displayed on the screen of a cathode ray tube in raster, dot matrix or other arrangements, and in systems in general in which high efficiency and accurate synchronization are required.
With the development of ever more complex and compact computer peripheral systems and subsystems such as displays, programmable displays and processors for programming and routing the logical functions between a central computer and groups of displays, the requirements for increased efficiency and accurate synchronization have been increased. The use of integrated circuitry in compact assemblies has made heat dissipation from conventional power supplies a problem, since more power must be generated within a smaller volume. The prior art series pass regulated power supply of approximately 30 percent efficiency has severe heat dissipation problems, and losses in the conventional switching regulator-converter design of approximately 60 percent efficiency cannot be tolerated in applications having small package requirements for the power supply.
In power supplies of the prior art, which have been employed in multiple display systems, the heat buildup at the switching and converter stages is such that a major portion of the system volume must be utilized to accommodate the heat which must be dissipated. Additionally, in many prior art systems, the frequency of operation of the switching power supply is not synchronized to the system so that transients and ripple from the supply can cause interference with circuit operation. In computer driven semiconductor memories, this is catastrophic since removal of power from the memory results in loss of data.